Tripping mechanism for punch presses



J. E. LOSHBOUGH TRIPPING MECHANISM FOR PUNCH PRESSES Filed Dec. 4, 1925 3 Sheets-Sheet 1 Oct; 9, 1928. v 1,686,622

' J. E. LOSHBOUGH TRIPPING MECHANISM FOR PUNCH PRESSES Filed Dec. 1925 5 Sheets-Sheet 2 8% 76m amo m Hornet Oct. 9, 1928.

. 1,686,622 J. E. LOSHBOUGH TRIPPING MECHANISM FOR PUNCH PRESSES Filed Dec. 1925 5 Sheets-Sheet 3 Eiflr.

Patented Qct. 9, 1928 JAMES LOSHBOUGH, OF ELKHART, INDIANA.

TRIPPING uncnnnrsm ron ruuonrnnssns.

Application m December 4, 1925. Serial No. 73,268.

This invention relates to improvements in power presses and particularly it refers to that mechanism in pressing, punching machines and the like by means of which the operator arbitrarily may either effect the stoppage of the press automatically after each cycle of operations, ormay efiect continuous operation.

It is, therefore, an object of the invention to incorporate with the drive of a power press a clutch and operator controlled means for locking the clutch in inoperative position, or for holding it in a position in vphich the operation is repeated,and to combine with it a non-repeat mechanism, by means of ,which the clutch is moved into inoperative position after each cycle of operations.

It is an object, furthermore, of the invention to effect the release movement of a clutch part by means of a projection on an operative organ of the machine, said projection passing a fixed point once in each operation, and influencing the movement of a control element through which a locking member is positively moved to a position in which it looks the clutch part against entry to operative position.

- With these and numerous other objects in view, an embodiment of the invention is described in tlha accompanying specification in Which reference is made to the drawings.

In the drawings: Fig. .1 is a side elevation of a press to which the clutch control mechanism is applied;-

I Fig. 2 is a front elevation, andpartly sectional view on alarger scale, of the clutch part and control elements; Fig. 3 is a side elevation of part of the control mechanism similar to that illustrated in in Fig. 1, but showing the parts in a. different I position, and on a larger scale,

Fig. 4 is a sectional view and part elevation of the clutch part and its carrier;

Fig. 5 is partly a front elevation and part- .45 1y a sectional view of the parts illustrated in Fig. 4;

Fig. 6is a bottom plan view partly in section of the locking member and clutch part;

- Fig. 7 isa detail sectional view ofa link connection between a manually operated part I and the automatic non-repeat mechanism;

Fi 8 is a sectional view through the parts .19 adapted to receive the means for normally -illustrated inFig. 7, seen from the opposite side, and I i hanging part4 on which the Fig. 9 is a detail sectional view on line 99 of Fig. '8.

The machine to be controlled by the appliance forming the subject matter of the present application is shown as a power press, having the pedestal 1, a frame 2 oscillatably mounted thereon, a press bed 3 and an overp-unching or pressing mechanisms proper of the machine, notillustrated in the drawing, maybe suitably guided. The arrangement of these parts does not form the present invention, and for this reason these parts are not described in detail in the specification.

The drive of the machine may be derived from some suitable source, not illustrated, and may be communicatedto the machine by means of the shaft 5 which is supported in bearin s one of which is indicated at 6 in Fig. 2 This shaft also loosely supports a combined flywheel and belt pulley .7 over which the driving belt, not shown, is trained.

While this flywheel or belt pulley 7 is loose- 1y mounted on the shaft, the latter supports fixed thereto a ring 8 acting as a-carrier for a clutch part 10 by which a driving relation between'the shaft 5 and the belt pulley 7 may be" established. I

The pulley 7 for this purpose is provided with sockets 9 one of which only is indicated in Fig. 2 in thatface of its hub which is next to the r1ng 8. The ring 8 is shown as com prising a portion of a larger and a portion of a smalldiameten. A preferably rectangular opening 11 extends axially through the portion of larger diameter and is continued as a groove 12 inthe portion ofsmaller diameter. Theopening 11 and groove'12 have a lining or guide bushing 13, Fig. 5, to facilitatesliding movement of the clutch part 10.

This part isconstructed as a pin of a crosssection corresponding to the area confined by the lining 13. A transverse groove 14 extends thru the pin intermediate its ends, advisably at such distance from the front end of the pin that in retracted position, Fig. 4, of this clutch pin one wall of the groove 14 is substantially flush with the rear face .of the portion of larger diameter of the ring 8. The bushing 13 is securedin place within the ring 8 b means of the screw 15.

The c utch partalso has an axial recess advancing the part to operative position,-

part 10 into the position shown in Fig. 4 the belt pulley 7 will rotate loosely on the shaft, while the shaft will remain at rest. It is, furthermore, obvious that normally the spring 16 acting on the clutch part 10 will cause the same to be advanced to clutch position. The invention, therefore, comprises means under the control of the operator of the machine for selectively, either locking the clutch part 10 against movement. to operative position, Fig. 4, or for releasing this look, in which latter case the clutch part 10 will automatically be advanced to operative position, Fig. 2. k

The locking member 20 is formed as a lever pivoted on the bolt 21 in a fixed part of the machine frame 2. The pivotal support of the lever 20 is so close to one end'of the same that this loekinglever will under its own weight assume the-position indicated in Fig. 3, in which it is withdrawn from locking position, so that the clutch part 10 will be advanced to clutch position. In Figs. 1 and 4, however, the locking member 20 is shown in locking position, preventing thereby the movement of the clutch part 10. The locking member 20 is so disposed with respect to the clutch part 10 that it'is adapted to enter the groove 14, even if this clutch part is fully advanced, Fig. 2, and the upper margin ofv the locking member 20 is for this purpose providedwith a beveled cam edge 22 facilitating the entry of this marginal part to operative position, and effecting by this entry into the groove14 of the clutch part a positive return movement of said part to inoperative position, Fig. 4, against the action of the spring 16.

To prevent upon withdrawal of the locking member 20 of the clutch element 10 from being advanced too far by the spring and be-;

ing pushed out of the squared opening 11, a safety stop 23 is indicated in Fig. .5, said stop comprising a pin disposed at a right angle to the direction of movement of the clutch part 10 and adapted to engage the clutch pin after the same has been advanced a predetermined extent. According to Fig. 2 this maximum advance of the clutch part. 10 brings the front face of the pin a slight distance from the bottom of the socket 9 in the driving pulley 7. 1 a

, The locking member 20 drops under its own weight automatically to inoperative or lock release position, Fig. 3. Means under control of the operator are provided for effecting the return of this locking member 20 to operative or lock position, and for holding it there.

A treadle lever 24 is pivoted at 25 in the pedestal and a rod 26 is flexibly connected to the treadle lever 25 intermediate-its ends; it carries at its top a connector 27 by means of which this rod 26 is movably associated with a bar 28. This bar isguided in two flanges, the flange 29 part of a bracket- 30 fixed to the frame 2, and the flange 31 being adjustable on the bracket 30 in a- Vertical slot, Fig. 1. The bar 28 forming an offset extension of the link 26 is surrounded in its lower portion by a spring 32 resting below on flange 29, while the top ofv the spring engages a collar 33 adjustably fixed on the rod 28. The spring 32, therefore, has a tendency to return the bar 28 and link '26 and treadle lever 24 to the position shown in Fig. 1 when the treadle is released, the spring urging the collar 33 against the flange 31.

Another spring 34 surrounds the upper portion of bar 28 between flange 31 and a washer 35 loosely mounted on this bar. The second spring 34, therefore, normally has a. tendency to force the washer 35 upward, regardless of the depression of the treadle.

,The control means for the locking member20 include in addition to'the elements described abell crank lever 36 mounted pivotally on a bolt 36 fixed in the machine. The arm 38 of this bell crank projects upward and is connected by links 37 with the locking member 20 intermediate the ends of the same, the latter being provided'with a transverse bore 39 through which the attachment pin for the links 37 extends. The arm 38, furthermore, has a lateral extension 40 terminating in an upwardly directed lug 41 of such height that the lever 36 assuming the'position shown in Fig. 1 will engage by means of the lug 41 the rear portion of the locking member 20 and will assist in forcing said locking member to operative -or locking position, Fig. 1. i The other arm 42 of the bell crank 36 is bifurcated at its free end, Fig. 9, the prongs 43 being provided with noses which rest upon the washer 35. A pin 44 is journaled transversely of and in the prongs 43 and is provided between them with a notch 45 of substantial depth and-having a flat bottom. A notch 46 in the extension 47 of bar 28 above the washer 35 has oppositely inclined end walls 48, 49 and a slightly slanting flat bottom wall 50, Fig. 8.

Normally the spring 34- forcing the arm 42 upward, Fig. 8, will urge the edge of the fiat part of notch 45 of pin 44 against the upper slanting bottom wall 48, whereby the bell crank, arm 42 is stopped against further upward movement.

A block 51 is slidably supported on the extenslon 47 of the rod 28 and is for this purpose equipped with a longitudinal bore 52 of a sufjecting laterally from'a prong 43 of the bell cnank arm 42', and fixedly connected with the reduced extension 53 is a lever 54. One arm ,/of this lever terminates in a lug 55 to which a link 56 is movably secured. The opposite arm has on its lower surface 'a socket 57 in opposition to a lateral socket 58 on :3. prong 43 ofthe bell crank lever 36.- A spring 59 is 1 seated in both of these sockets, Fig. 7, thereby normally forcing the opposite end of the lever 54 downward, Figs. 1, 7 and 8.

The pivot 21 on which the locking member 120 is mounted also carries a control lever 60 0 having one end directed towards the clutch carrying ring i and being provided adjacent said end with cam nose 61 for engagement 3 with a release cam 62 which is secured in the circumference of the clutch ring 8'and which at each revolution of the clutch ring therefore once engages the cam nose 61 of the control lever 60 to depress the same about its pivot 21.

The control lever 60 for the locking member is extended beyond this fulcrum 21 and is bifurcated at 63, the prongs of the fork having upward extensions 64': The upper threaded part of link 56 is inserted into this fork, and a sleeve stop 65 is slidably securd on the link to impinge with its lower end on the control lever 60 while 'upward movement is prevented by the adj ustahle nut 66 on top of the sleeve. It is obvious, therefore, that upon suitable adjustment of thesleeve stop, the link 56 will be held within. the fork 63 of the control lever 60, while upon loosening of the nut 66 and displacement of the stop 65 the link 56' may be readily disconnected.

When in the operation of the press it is des red to establish and maintain the drive of shaft 5, the link 56 may be disconnected, or even .the control lever V tinned, a further downward move ent of'bar 28 will now also cause the pin to move oo along with it downward,- and this naturally also moves'the arm 42 of bell crank 36 down about its pivot 36', removing'the holding lug 41 from the rear. end of locking'member 20, so

' that the latter drops to release position, aid; owed by the links 37. The parts are shown in 60 may be removed] The operator, depressing the treadle lever 24 however the depression of the treadle is con this position in Fig; 8, in which, however, the link 56 is showninplace. v

Spring 16 in the ring 8 now forces the clutch pin 10 into a socket 9 in the flywheel 7, as soon as this socketis in opposition to the pin, and the shaft 5 is then'ppsitively driven with the flywheel or belt pulley.- d In each rotation of the ring 8 the projection 62 on its circumference may enter-into engagement with the control lever 66 and may t-ilt the same. .But'sipce the rear bifurcated.

end 63 of this lever is in this operation not connected with the link 56, this tilting move- 'ment will haveno influence on the operator controlled parts. The press, therefore, will 7 continue to operate until the operator releases -the treadle, so that the pin 44 through the spring enforced upwai'd movement of the rod 28 is forced upward, tilting, arm 42 upward and pushing thereby by means of links 37 and arm 41 the locking member 20 positively into locking position, and retaining it in this position until the t'readle is again depressed.

Normally, pedal 24 is depressed by the operator, and to gain another. revolution f the press crank-shaft, and thereby amovg- I the pedal 24 is rement of the press ram, leased and again depressed. When the pedal 24 is thus released, as above mentioned, the spring 34 actuates the bell-crank 36v back to the position indicated in Fig. 1 and rods 28 and 47 are elevated thereby, causing pin 44 to engage notch 48. The press is then ata standstill as locking lever, or latch, 20, is raised and the lock bolt or clutch 10 has been retracted thereby. WVhen the pedal 24 is again depressed, as above mentioned, the rods 28 and 47 are drawn downward thereby, the bell-crank lever arm 42, which is connected with the pin 44' by the fork 43, being tilted downward thereby, due to the engagement of the pin 44 with notch 48 in rod extension 47, whereby the arm of said bell-crank lever and the locking 'lever or latch 20 are lowered, the latter through link 37, thereby releasing the lock. bolt 10 which again :enters the wheel bolt socket. The press crank-shaft then rotates and a single opera-' disk 8 is rotated with the shaft 5 and. the cam 62 thereupon engages the end of the tripping lever adjacent said disk, tilting said lever, the opposite end 63 of said lever being upwardly tilted thereby, whereby'thc link 56 tilts. the lever 54 upward, thereby disf engaging the pin 4413mm the-notch 48.

Thereupon, the spring 34, which engages beneath the rodflange or disk 35, and upon which disk'the, fork 43 of bell-crank lever arm 42 is seated,'t ilt's said arm 42 upward, 'the'reby sliding the block 51 upward along the rod ;4 7 and carrying the detent pin 44' tive movementof the pressis'etlected. The I y to a. point above the notch 48 and in slidablc surface of said'rod exengagement with th pward tilting movetension. Thus, with isu" ment of the bell-crank lever arm 42, the link 37 elevates the locking lever or latch 20 and the lock bolt- 10 is again retracted thereby; and the point 41 of the bell-crank lever arm .40 again engages the base of the lever 20 and aids in maintaining the latter in the elevated position, also limitingthe upward swing of the-bell-crank lever arm 42. The press is now at a standstill. For convenience, the rocking pin 44 may be designated as a detent element or pin, and when the link 56 is connected with the lever 60, the tripping lever 60, the portion 63 thereof, the link 56 and lever 54 may be designated as tripping mechanism.

hen it is desired, however, to automatically interrupt-the press after each complete revolution of the shaft 5, the lever 54 fixedly attached to the pin 44 is connected by means of the link 56 to the bifurcated end 63 of the control lever 60, and the sleeve stop 65 is applied to maintain this connection The inactive position of the press is again as shown in Fig. 1. l/Vhen now the operator depresses the treadle lever 24 and pulls the rod 28 downward, the pin 44 again will engage Wall 48 of the notch in the extension 47, and continued depression of the treadle'will again cause release of the locking member 20, as described above. In this instance the down.- ward movement of link 56 also will cause the front end 61 of the control member 60 to move closer to the path of the projecting pin 62. I

If now, however, upon completionof a cycle of operations, that is, upon one complete revolution of the shaft 5, the lug 62 on the clutch ring'8 strikes the cam surface crank 36 from the position shown'in Fig. 3 to the position ofF-ig. 1. The links 37 connecting the bell crank 36 with the locking member 20 will again push said lockingmemher back into the transverse groove 14 of the clutch pin to force the latter back against the action of spring 16. The holding lug 41 of the bell crank lever 36 again will act on the rear end of, the locking member 20 to prevent the drop of the same to "inoperative position. i

This return tilting movement of the bell crank 36 is effected in spite of the fact that the operator holds the treadle and bar 28 depressed. If it is then desired to start the press againand to have it execute a single stroke followed by a rest period, the operator again first releases the threadle and then again depresses it to bring the parts oncemore into the position shown in Fig. 3.

I claim:

1. In a power press, the combination with a driven shaft, a driving wheel, a spring pressed locking bolt adapted for alternate engagement and disengagement with said driving wheel, and a tiltable locking lever with said foot-pedal rod,v and disengaging means operatively connecting said detent means with said tripping lever for disengaging said detent means from said rod when said tripping lever is tilted by said cam.

2. In a power press, the combination with a driven shaft, a driving wheel, a spring pressed locking bolt adapted for alternate engagement and disenga ement with said driving wheel, and a tiltab e locking lever adapted to alternately retract and release said looking bolt, of a cam on said driven shaft, a tripping lever tiltably mounted intermediate its extremities and adapted to be tilted by said shaft cam, a bell-crank lever, actuating linkage connecting said bell-crank lever with said locking lever, spring means effecting pressure upon one arm of the bell-crank lever for nor-- mally urging-the latter for locking lever actuation to retract said locking-bolt, a spring pressed foot-pedal, a rod connected with said pedal, detent means carried by one arm of said bell-crank lever and engageable with a recess in said pedal rod, said detent means including a spring pressed rotary element journaled in said bell-crank lever arm. and disengageable linkage-operatively connecting said detent means with said trlpping lever for disengaging said detent means fromlsaid rod when said tripping lever is tilted by said cam.

3. In a power press, the combination with a driven shaft. a" driving wheel, a-spring IUU pressed locking'bolt adapted for alternate engagement and disengagement ,with said driving wheel, and a tiltahle'lo'cking lever adapted .to alternately retract and release said locking bolt, of a cam on said driven shaft, a tripping lever tiltably mounted intermediate its extremities and adapted to be tilted by said shaft cam,a bell-crank lev er, a link connecting said bell-crank lever with said locking lever for actuating the latter, a lateral projection from one of the bell-crank lever arms adapted to engage the locking lever whe'nthe latter engages said locking bolt, spring means normally urging said bellcrank lever for actuating said locking lever said sgrmg means on said bell-cranklever,

and di tively connecting said detent means with sald engageable disengaging means operatripping lever for disengaging said detent means from said rod when said trippinglever is tilted by said cam. I

4:. In a power press, the combination with a driven shaft, a driving wheel, a spring pressed locking boltadapted for alternate engagement and disengagement with said driving wheel, and a tiltable locking lever adapted to alternately retract and release saidv locking bolt, of a-cam on said driven shaft, 21 tripping lever tiltably niounted intermediate its extremities and, adapted'to be tilted by said shaft cam, a bell-crank lever-provided with a forked arm, actuating linkage connecting one arm of said bell-crank lever with said locking lever for actuating the latter when the former is tilted,.s pring means. effecting pressure upon sa' forked bell-crank lever arm for normally ging the latter to effect lo cking 1everactuati0n to retract said locking bolt, a spring pressed foot-pedal a rod connected with said pedal and movable therewith, detent means carried by the forked arm of said bell-crank lever and engageablewith a recess in said pedal rod, said detent means including a detent pin rotatably mounted in said bell-crank lever arm fork,

.a block in which said pedal rod is slidably mounted, and appringpressed lever connected one end of said rotary detent pin,

and disen ageable disengaging means operatively connecting said detent means spring pressed levenwith said tripping lever for disengaging said detent pin from said rod recess when said tripping lever is tilted by said shaft cam; I

5. In a power press, the combination with a driven shaft, a driving wheel, a spring pressed locking engagement and disengagement with said driving wheel, and a tiltablelocking lever adapted to alternately retract and release said locking shalt, a tripping lever tiltably mounted intermediate its extremities and adapted. to be tilted by said shaft cam, a bell-crank lever provided with a, forked arm, actuating linkage connecting one arm of said bell-crank lever with said locking-lever for actuating thelatter when the former is tilted, spring.

means for effecting resilient pressure upon said forked bell-crank lever arm for normally urging the latter to effect locking lever aetuation to retract said locking bolt, a spring pressed foot-pedal, a rod connected with said pedal and movable therewith, detent means carried by the forked arm of said bell-crank 'lever and engageable with a recess in said pedal rod, said detent means including a block arranged in the fork of said bell-crank lever forked arm, a detent pin 'rotatably 'mounted in said blockand bell-c'rank lever arm fork and in communication with a bore in said block in which said p al rod is slidable, and a spring pressed detent pin actuating lever mounted upon one and of said pin, and a disengageable disengaging link operatively connectin said detent means-spring pressed lever. wit said tripping lever for disengagingisaid detent in from said rod recess when said tripping lever is tilted by said shaft cam. I

witness whereof I have hereunto aflixed my signature thisl28th day of November, 1925.

JAMES E; LOSHBOUGH.

bolt adapted for alternate 

